Safe haven in a storm

If lightning strikes your car, the metal body absorbs the current on its outside surface, keeping you safe inside. (JANEK SKARZYNSKI/AFP/GETTY IMAGES)

We delved into a few urban driving legends last week. Let's pick apart two more: the safest place to be during a lightning storm is in your car, and red cars attract more speeding tickets than less-colorful vehicles.

Lightning legend

You've undoubtedly heard this saying. But you might not know the real reason why it's safer to be in a car than being outside during a storm.

"It's not because of the rubber tires, as people often claim," said Daniel Davis, a physicist who narrates the Boston Museum of Science's famous lightning show. "You're safe riding inside the T, for example, and the T has metal wheels. You're very safe inside a plane. Most commercial airplanes are struck by lightning once a year on average and there's very little damage. They're airborne, and the rubber tires have been pulled up into the fuselage."

Cars and other metal structures are predominantly safe havens from lightning for two distinct reasons, Davis said. First, they are great conductors of electricity. Second, when cars and the like are struck by lightning, the current stays on the outermost surfaces of their metal frames. No matter where you touch inside the car, you won't get zapped.

"The charge is pushed to the outside skin of the conductor. It's called a skin effect," Davis said.

The science behind this phenomenon goes something like this, explains Davis: A bolt of lightning might last but a second, but during that moment, the intensity of the current fluctuates several times. The current might start at 100,000 volts, jump up to 1 million volts, then slide back down to 500,000 volts, all within a second. The fluctuations create a magnetic field in the object that's being struck, such as your car, and that magnetic field pushes the current to the outside surfaces of the object.

"We do a very similar demonstration at the Theater of Electricity in the Museum of Science," Davis said. "We have a [human-size] metal bird cage with one-quarter-inch-thick iron bars that's struck by our 1-million-volt Van de Graaff generator. Visitors regularly touch the inside of the cage as it's being struck and they don't feel anything. Certainly, they are not harmed."

Davis added a few points of caution, however. A car will conduct the electricity from a lightning strike with the windows open or closed. But if you were to stick out your hand, the charge would likely jump to your skin.

While being in a car is safer than being outside during a lightning storm, it's probably only slightly safer than being in a house. (A house's electric wiring and plumbing will soak up the charge from a strike.)

Likewise, you might be "marginally safer" in a larger vehicle than, say, a Mini Cooper. "But if a lightning storm were coming, I certainly wouldn't waste any time debating which vehicle to get in. I'd pick the closest one," Davis said.

It's also a good idea to pull over, not because a lightning strike will affect your engine, but because you might be blinded by the flash and lose control.

Lastly, although cars are excellent electrical conductors, there's an extremely remote chance that you could still be hurt.

"Your chances of being struck by lightning are very, very small - about 1 in 3 million," Davis said. "But I'd hesitate to say you're absolutely safe in any place. It's possible with a particularly strong stroke that something would happen."

Seeing red

People wear red when they want to get noticed, so it stands to reason that red cars get noticed more often by the police, right?

This legend is an ancient one, with tons of theories on the Web about its accuracy, or lack of. (Police everywhere, not surprisingly, say it's completely false.)

One of the better myth-busting websites, www.snopes.com, has a nice feature on the subject. The story mentions a number of possible explanations - the color red produces an optical illusion that makes the car seem faster; seeing red increases police officers' heartbeats, etc. But ultimately, it dismisses the theory by referencing a St. Petersburg Times survey on red cars and speeding tickets.

A reporter, who was attempting to answer the same question I am, jotted down the colors of 1,198 cars to approximate the percentage of red cars in his county. He then categorized the 924 most-recently issued speeding tickets according to vehicle color.

"Red cars accounted for 14 percent of the vehicles surveyed on the road and got about 16 percent of the speeding tickets, not a significant difference," the newspaper's reporter found.

The Times survey, conducted in 1990, is somewhat convincing. But I wanted more proof.

The Massachusetts Merit Rating Board, the agency responsible for tracking all of our state's speeding tickets, does not track them according to car color. So for a second opinion, I turned to Mark Fairchild, a research professor at the Rochester Institute of Technology's Munsell Color Science Laboratory.

Fairchild not only holds a doctorate in vision science, he drives a red BMW sports car, too!

"I bought my first red BMW in 1997, turning in my blue Honda Civic. And I got a speeding ticket on the third day," Fairchild said. "My friends said, 'You're an idiot, Mark. You should have known. You're a color scientist!' "

All joking aside, Fairchild said, that's not why he got the speeding ticket.

"I was going 45 in a 30 mile-per-hour zone, and I didn't know it," he said.

Because red is a bright color, it does indeed stand out against darker backgrounds, Fairchild said. But from a scientific standpoint, red doesn't have any magical or intrinsic properties that would grab an officer's attention.

"It tends to have a connotation as an emergency color, or a stop sign color, so it does tend to get noticed. But you're going to get noticed if you're speeding no matter what car you're driving," Fairchild said.

Certain colors can indeed trigger memories, like the smell of an apple pie may remind someone of his grandmother, Fairchild said. But those triggers have everything to do with the individual's makeup and nothing to do with the color itself.

"It's a personal thing," Fairchild said. "I get these questions all the time. 'What color should I paint my room to make me happier?' My response is, whatever color you like. Red might make me happy and excited; it might make you depressed. And it tends to be very small effects."

If anything, Fairchild said, he believes that police may be biased against sports cars, which by design go very fast. "And they tend to be red more often," he said.

Interestingly, because of the way our eyes are constructed, red is a difficult color to see at night, Fairchild added. So if you drive a red car at night, it will actually be more difficult for a police officer to notice you.